:root{--bg-color:#f9fafb;--surface-color:#fff;--text-primary:#111827;--text-secondary:#6b7280;--accent-color:#3b82f6;--accent-hover:#2563eb;--border-color:#e5e7eb;--shadow-soft:0 4px 12px #00000008;--transition-speed:.25s}[data-theme=dark]{--bg-color:#0f0f11;--surface-color:#18181b;--text-primary:#f3f4f6;--text-secondary:#9ca3af;--accent-color:#60a5fa;--accent-hover:#3b82f6;--border-color:#27272a;--shadow-soft:0 4px 20px #0006}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-color);color:var(--text-primary);transition:background-color var(--transition-speed), color var(--transition-speed);-webkit-font-smoothing:antialiased;flex-direction:column;min-height:100vh;font-family:Inter,-apple-system,system-ui,sans-serif;display:flex}.navbar{background-color:var(--surface-color);border-bottom:1px solid var(--border-color);z-index:100;justify-content:space-between;align-items:center;padding:1rem 3rem;display:flex;position:sticky;top:0}.logo{letter-spacing:-.02em;font-size:1.25rem;font-weight:800}.logo span{color:var(--accent-color)}.time-display{color:var(--text-secondary);background:var(--bg-color);border:1px solid var(--border-color);border-radius:6px;padding:.4rem .75rem;font-family:monospace;font-size:.85rem}.nav-links ul{gap:1.5rem;list-style:none;display:flex}.nav-links a{color:var(--text-secondary);font-size:.9rem;font-weight:500;text-decoration:none}#toggle-theme{cursor:pointer;border:1px solid var(--border-color);color:var(--text-primary);background:0 0;border-radius:6px;margin-left:1rem;padding:.4rem .8rem;font-size:.85rem}.main-container{flex-direction:column;flex:1;justify-content:flex-start;align-items:center;width:100%;max-width:1000px;margin:0 auto;padding:3rem 2rem;display:flex}.hero-section{text-align:center;margin-bottom:2.5rem}.hero-section h1{letter-spacing:-.04em;margin-bottom:.5rem;font-size:2.25rem;font-weight:800}.hero-section p{color:var(--text-secondary);font-size:1rem}.converter-box{background-color:var(--surface-color);border:2px dashed var(--border-color);text-align:center;width:100%;transition:all var(--transition-speed);border-radius:16px;margin-bottom:3rem;padding:6rem 2rem}.converter-box:hover{border-color:var(--accent-color);background-color:var(--accent-hover);background-opacity:.05}.file-label{cursor:pointer;flex-direction:column;align-items:center;gap:1rem;display:flex}.upload-icon{filter:grayscale();opacity:.5;font-size:3rem}#selected-files{flex-direction:column;gap:1.5rem;width:100%;list-style:none;display:flex}.file-card{background:var(--surface-color);border:1px solid var(--border-color);width:100%;box-shadow:var(--shadow-soft);border-radius:12px;flex-direction:column;display:flex;overflow:hidden}.file-header{background:var(--bg-color);border-bottom:1px solid var(--border-color);justify-content:space-between;align-items:center;padding:.75rem 1.25rem;display:flex}.file-name{color:var(--text-primary);white-space:nowrap;text-overflow:ellipsis;flex:1;margin-right:2rem;font-size:.9rem;font-weight:600;overflow:hidden}.file-meta{align-items:center;gap:1.5rem;display:flex}.file-size{color:var(--text-secondary);font-family:monospace;font-size:.8rem}.copy-btn{background-color:var(--accent-color);color:#fff;cursor:pointer;border:none;border-radius:6px;padding:.4rem 1rem;font-size:.75rem;font-weight:700;transition:transform .1s}.copy-btn:active{transform:scale(.95)}.copy-btn.success{background-color:#10b981}.preview-window{background-color:var(--surface-color);justify-content:center;align-items:center;width:100%;height:300px;display:flex;overflow:auto}.preview-window img{object-fit:contain;max-width:100%;max-height:100%}.preview-window pre,.preview-window embed{width:100%;height:100%;color:var(--text-secondary);border:none;padding:1.5rem;font-size:.85rem;line-height:1.6}.placeholder-text{text-align:center;color:var(--text-secondary);padding:3rem;font-style:italic}